Which kingdom is characterized by organisms that obtain energy by absorbing nutrients from the environment, often decomposing organic material, and have chitin in their cell walls?

• A. Protista
• B. Plantae
• C. Animalia
• D. Fungi

Answer: (D)

Fungi feed by absorbing nutrients from their surroundings after extracellular digestion. They secrete enzymes that break down organic material outside their bodies and then take up the resulting small molecules, which makes them effective decomposers in ecosystems. They also have cell walls made of chitin, a strong polysaccharide different from the cellulose walls of plants and the lack of cell walls in animals. This combination of absorptive nutrition, ecological role as decomposers, and chitin-containing cell walls uniquely points to fungi among the major kingdoms.